Watercress

Watercress provides vitamins A, B6, folic acid, C, and K; the minerals iron, calcium, iodine, and manganese; and beta-carotene and lutein. Watercress is related to cabbages and mustard greens and provides some of the same sulfur compounds that have been found to be protective against some forms of cancer and heart disease. It is more than 95 percent water and extremely low in calories.
Nutritional Facts :
One cup of chopped watercress provides 4 calories, 0.4 g carbohydrate, 0.8 g protein, 0 g fat, 0.6 g dietary fiber, 1598 IU vitamin A, 14 mg vitamin C, 4 mcg folic acid, 112 mg potassium, 14 mg sodium, 20 mg phosphorus, 40 mg calcium, and 8 mg magnesium.